US Combat Troops Enter Vietnam
In March 1965, two battalions of US Marines came ashore at Da Nang in South Vietnam, the first American ground combat units officially deployed to the country. Their arrival marked the shift from an advisory role to a full-scale American war that lasted until 1975. The conflict killed millions of Vietnamese, cost the lives of more than 58,000 Americans, and reshaped US politics, military thinking, and public trust in government.
The roots of the intervention lay in the Cold War. After the Viet Minh defeated France in 1954, the Geneva Accords divided Vietnam temporarily at the 17th parallel, with a communist government in the north under Ho Chi Minh and an anti-communist state in the south. Successive American presidents, guided by the belief that the fall of one country to communism might topple its neighbors, sent money, weapons, and military advisers to Saigon. By the early 1960s, a communist-led insurgency in the South, backed by North Vietnam, was gaining ground against an unstable government.
The turning point came in August 1964, when American destroyers reported attacks by North Vietnamese boats in the Gulf of Tonkin. Historians still debate details of the second reported incident, which is now widely believed not to have happened as first described. Congress nevertheless passed the Gulf of Tonkin Resolution, giving President Lyndon Johnson broad authority to use force. In early 1965, a sustained bombing campaign against the North, called Operation Rolling Thunder, began, and the Marines were sent to protect the air base at Da Nang. Their mission soon expanded from defense to offensive operations, and troop levels climbed from a few thousand to roughly 180,000 by the end of 1965, eventually peaking at over 500,000 in the late 1960s.
The war proved difficult to win by conventional means. US forces held a large advantage in firepower, but fought an enemy that blended into the population, used tunnels and jungle sanctuaries, and could choose when to fight. The Tet Offensive of early 1968, though a military setback for communist forces, shook American confidence and fueled a growing antiwar movement at home.
President Richard Nixon began withdrawing troops under a policy called Vietnamization, and the last American combat forces left after the Paris Peace Accords of January 1973. Fighting between North and South continued, and Saigon fell to northern forces in April 1975, unifying the country under communist rule.
The legacy was profound. In the United States, the war deepened public distrust of government, led to the end of the draft, and prompted the War Powers Resolution of 1973. In Vietnam, Laos, and Cambodia, it left lasting damage from bombing, defoliants, and unexploded ordnance.